Forest biomass assessment in Vietnam using Alos/Palsaral

Abstract

This paper presents a preliminary assessment of ALOS/PALSAR data from the Kyoto and Carbon Initiativeprogram for monitoring of forest status and mappingof biomass in Vietnam. The changes in forest status (deforestation, reforestation, growth) occurred during three years (2007-2008-2009) were detected in a region of intensive rubberplantation program. Biomass estimation has been estimated in aprovince of active tree planting. Optical data (SPOT 5) have been used for mapping of forest types and in-situ biomass measurements have been used to analyse PALSAR data. The resulting biomass map of the Hoa Binh province has been validated using forest inventory data. The results obtained indicate that the forest biomass is relatively low (average values less than40 ton/ha). This is due to the shortened exploitation cycle of the forest plantation (harvest of acacia mangiumspecies after 4-5 years instead of 6-8 years). This change in the forest exploitation practices effects the carbon stock of the region, and will need to be accounted for in the carbon budget calculations.ALOS PALSAR data proved particularly useful for providinginformation relevant to carbon budget calculation and to the assessment of forest states, from logging to regrowth during the first decades after disturbances in Vietnam. Futureworks will consist of applying the methods developed to the entire Vietnam, for the present period starting from 2007.